Alright. I might take the risk to buy it, and just file a bit if it's too tight...
But I don't really like the full stock look, and the grip is even worse :s (and I love so much the sliding stock + Aimpoint CompM2 + M900AB
)
I've just thought about it, maybe a stick type could fit into a folding stock? Else I'll have a look into R/C LiPos... There's probably a bigger choice. They don't usually use Tamiya connectors, but it isn't a thing too hard to change!
As for the mechbox, mine is a stock TM one. I'm usually quite conservative with my ammo, so I hope it wouldn't be too bad.